CN103066952B - Built-in oscillation circuit - Google Patents

Abstract

The invention provides a built-in oscillation circuit. A negative feedback closed loop circuit type is adopted for the built-in oscillation circuit, and a frequency-voltage conversion mode is used for the built-in oscillation circuit, and therefore the built-in oscillation circuit is enabled to be completely integrated in a chip, crystal oscillators needing to be additionally arranged are saved, and process cost is saved. An oscillation frequency generated by an annular oscillator is converted into a feedback voltage and compared with a reference voltage, then compared results are fed back to a control end of the annular oscillator, the frequency of the annular oscillator is changed, the output frequency deviation is compensated, and therefore work frequency with low temperature drift is output by a loop circuit, and output frequency with high precision is generated.

Description

Built-in oscillation circuit

Technical field

The present invention relates to oscillating circuit equipment, particularly relate to a kind of built-in oscillation circuit.

Background technology

Making rapid progress of science and technology, makes the developing trend low-power consumption of various equipment, and the little and low cost of area, clock generating circuit also trends towards in full sheet integrated accurately, high accuracy, high-frequency future development.Pierce circuit is generally used for providing clock signal to various integrated circuit (IC) chip.Generally the pierce circuit of clock signal is provided to have to various circuit chip following several:

A kind of is generation circuit based on ring oscillator.Ring oscillator produces circuit and uses comparatively extensive, but in CMOS technology, owing to there is the unsteadiness of temperature, technique and supply voltage, makes the output frequency stability of described Embedded clock circuit poor.

Another is lax (Relaxation) oscillator of RC, and because its frequency accuracy is higher, current development is comparatively rapid, but due to the operating frequency of RC relaxation oscillator lower, be therefore not suitable for the clock signal application of upper frequency.

Another kind is also that comparatively commonly clock signal adopts quartz crystal (Crystal) oscillator electricity as clock reference.

At present for consumer electronics product, such as 27/49M, the radio-frequency (RF) emission system of 315/433M frequency range, what the pierce circuit as generation clock reference generally adopted is all the third structure, Fig. 1 is the structural representation of clock signal generating circuit in prior art, as shown in Figure 1, crystal oscillator produces signal by oscillator, and is locked by PLL/DLL and obtain clock signal.Need to obtain suitable clock signal with phase-locked loop (PLL) or delay locked loop (DLL) at chip internal (namely on sheet).This pierce circuit can realize very high precision (1 ~ 100ppm), but this scheme needs the extra external crystal-controlled oscillation increased, not only drastically increase the cost of product, and need to take larger chip area and power consumption, and reduce the competitiveness of whole chip, therefore affect at some to the application in the consumer product of cost compare sensitivity, such as toy remote control product, controlled in wireless product and infrared remote control product etc.

Summary of the invention

The object of the invention is to solve the deficiencies in the prior art, a kind of novel built-in oscillation circuit be provided, solve the frequency shift (FS) that the change due to technique, supply voltage and temperature produces, and with low cost, frequency range larger built-in oscillation circuit.

For solving the problem, the invention provides a kind of built-in oscillation circuit, comprising basic current and producing circuit, ring oscillator, frequency-photovoltaic conversion circuit and differential amplifier circuit;

Described basic current produces circuit and comprises the first operational amplifier, the first amplifier tube, trimming resistors and mirror image circuit, described first operational amplifier receives a reference voltage, after described trimming resistors trims, export an intermediate current by the first amplifier tube, described intermediate current exports reference current through described mirror image circuit;

Described ring oscillator produces frequency signal;

Described frequency-photovoltaic conversion circuit comprises switching tube module, charge and discharge electric capacity and output capacitance, described switching tube module receives described reference current and frequency signal, and under the control of described frequency signal, carry out described reference current is charged to described charge and discharge electric capacity and carry out between charge and discharge electric capacity and output capacitance the process that electric charge is redistributed and discharged to described charge and discharge electric capacity, to make described output capacitance output feedack voltage;

The more described feedback voltage of described differential amplifier circuit and reference voltage also produce control voltage, and described control voltage carries out feedback compensation to the frequency signal of described ring oscillator, export until frequency signal is stable.

Further, when the frequency signal of described ring oscillator stablizes output, the value of described frequency signal is relevant with the capacitance of the resistance value and charge and discharge electric capacity that trim resistance.

Further, the output frequency of described built-in oscillator is:

$\mathrm{fout}=\frac{K}{\mathrm{Cc}*(\mathrm{Rp}+\mathrm{Rn})},$

Wherein, fout is the output frequency of described ring oscillator, and Cc is the capacitance of described charge and discharge electric capacity, and (Rp+Rn) is the resistance value of described trimming resistors, and K is proportionality coefficient.

Further, produce in circuit at described basic current, two inputs of described first operational amplifier connect the first link of described reference voltage and the first amplifier tube respectively, export the control end of the first amplifier tube described in termination; First link of the first amplifier tube described in described trimming resistors one end ground connection, another termination, the second link, the output of the first amplifier tube described in the input termination of described mirror image circuit export described reference current.

Further, described mirror image circuit comprises the first mirror image efferent duct, the control end of the first amplifier tube described in the control termination of described first mirror image efferent duct, the first link of described first mirror image efferent duct export described reference current, described first mirror image efferent duct second connect supply voltage described in termination.

Further, described mirror image circuit comprises the first mirror image input pipe, second mirror image input pipe, first mirror image efferent duct and the second mirror image efferent duct, second link of the first amplifier tube described in the control termination of described first mirror image input pipe, first of described first mirror image input pipe connects the second link of the second mirror image input pipe described in termination, second of described first mirror image input pipe connects termination one supply voltage, second of described second mirror image input pipe connects the second link of the first amplifier tube described in termination, the control end of the first mirror image input described in the control termination of described first mirror image efferent duct, first of described first mirror image efferent duct connects the second link of the second mirror image efferent duct described in termination, second of described first mirror image efferent duct connects supply voltage described in termination, the control end of the second mirror image input pipe described in the control termination of described second mirror image efferent duct, first link of described second mirror image efferent duct exports described reference current, second link of described second mirror image efferent duct is connected with the first link of one first mirror image efferent duct.

Further, described mirror image circuit is the overriding mirror image circuit of multichannel, described trimming resistors realizes low level frequency departure to described reference current and regulates, and the overriding mirror image circuit of described multichannel realizes high-order low level He Ne laser and described reference current realizes high-end frequency bias adjustment.

Further, described overriding mirror image circuit is common-source common-gate current mirror structure.

Further, the overriding mirror image circuit of described multichannel comprises the first mirror image input pipe, second mirror image input pipe, multiple first mirror image efferent duct and multiple second mirror image efferent duct, second link of the first amplifier tube described in the control termination of described first mirror image input pipe, first of described first mirror image input pipe connects the second link of the second mirror image input pipe described in termination, second of described first mirror image input pipe connects termination one supply voltage, second of described second mirror image input pipe connects the second link of the first amplifier tube described in termination, the control end of the first mirror image efferent duct described in each all connects the control end of described first mirror image input pipe, second of first mirror image efferent duct described in each connects supply voltage described in termination, the control end of the second mirror image efferent duct described in each all connects the control end of described second mirror image input pipe, the described reference current of rear output that is connected of described second mirror image efferent duct, described in each, the second link of the second mirror image efferent duct is connected with the first link of one first mirror image efferent duct.

Further, described built-in oscillation circuit comprises M the first mirror image efferent duct, described basic current produces circuit and receives a multidigit control signal, described multidigit control signal comprises He Ne laser position, mirror image circuit regulates position and resistance adjustment position, the ratio value that described He Ne laser position controls N number of described first mirror image efferent duct and described first mirror image input pipe is selected to realize frequency range, described mirror image circuit regulates the ratio value of a position control L described first mirror image efferent duct and described first mirror image input pipe to realize coarse adjustment in frequency range, described resistance adjustment position controls the resistance value of described trimming resistors to realize accurate adjustment in frequency range, wherein, N, L and M is positive integer, described N number of first mirror image efferent duct and L the first mirror image efferent duct are the first different mirror image efferent ducts, and N+L=M.

Further, described frequency-photovoltaic conversion circuit also comprises pulse signal generating circuit and parasitic capacitance eliminates circuit, described pulse signal generating circuit produces the pulse signal of multiple control switch module according to described frequency signal, described parasitism elimination circuit comprises the first parasitic elimination circuit and the second parasitism eliminates circuit, described charge and discharge electric capacity comprises the first charge and discharge electric capacity and the second charge and discharge electric capacity, described switching tube module comprises the first switching tube, first charging valve, first discharge tube, second switch pipe, second charging valve, second discharge tube, first anti-crosstalk pipe and the second anti-crosstalk pipe,

Frequency signal, first described in the control termination of described first switching tube connects reference current described in termination, second and connects termination first node, the inversion signal, first of frequency signal described in the control termination of described second switch pipe connects reference current described in termination, second and connects termination Section Point

Described first charge and discharge electric capacity one end connects described first node, other end ground connection, and described second charge and discharge electric capacity one end connects described Section Point, other end ground connection,

The control termination pulse signal of described first charging valve, two links connect between first node and output capacitance respectively, the control termination pulse signal of described second charging valve, two links connect between Section Point and output capacitance respectively, the control termination pulse signal of described first discharge tube, two links are ground connection and first node respectively, the control termination pulse signal of described second discharge tube, two links are ground connection and Section Point respectively

Described first parasitic capacitance is eliminated circuit input end and is connect described pulse signal, exports first node described in termination, and the described second parasitic circuit input end of eliminating connects described pulse signal, exports Section Point described in termination;

The control termination pulse signal of described first anti-crosstalk pipe, two links are connected between described first charging valve and output capacitance, and control termination pulse signal, two links of described second anti-crosstalk pipe are connected between the second charging valve and output capacitance.

Further, described switch module also comprises the 3rd discharge tube and the 4th discharge tube, the control termination pulse signal of described 3rd discharge tube, two connects described in terminations between the first charge and discharge electric capacity and ground, and the control termination pulse signal, two of described 4th discharge tube to connect described in terminations between the second charge and discharge electric capacity.

Further, described first switching tube, the first charging valve, the first discharge tube, second switch pipe, the second charging valve, the second discharge tube, the first anti-crosstalk pipe, the second anti-crosstalk pipe, the 3rd discharge tube and the 4th discharge tube receive different pulse signals, and described first switching tube, the first charging valve, the first discharge tube, second switch pipe, the second charging valve, the second discharge tube, the first anti-crosstalk pipe, the second anti-crosstalk pipe, the 3rd discharge tube and the 4th discharge tube are metal-oxide-semiconductor.

Further, the described first parasitic elimination circuit is identical with the structure of the described second parasitic elimination circuit.

Further, the described first parasitic circuit of eliminating has the 3rd node, and the parasitic capacitance of described 3rd node is equal with the parasitic capacitance of described first node.Described first parasitic circuit of eliminating comprises the 11 metal-oxide-semiconductor to the 17 metal-oxide-semiconductor, source electrode and the grid of described 11 metal-oxide-semiconductor connect, drain electrode connects described 3rd node, the grid of described 13 metal-oxide-semiconductor connects pulse signal, drain electrode connects described 3rd node, source electrode connects the source electrode of described 12 metal-oxide-semiconductor, the grid of described 12 metal-oxide-semiconductor connects pulse signal, source electrode and drain electrode connect and connect described reference voltage, the drain electrode of described 14 metal-oxide-semiconductor and the 15 metal-oxide-semiconductor all connects described 3rd node, grid and source grounding, the drain electrode of described 16 metal-oxide-semiconductor connects described 3rd node, grid connects pulse signal, source electrode connects the source electrode of described 17 metal-oxide-semiconductor, the grid of described 17 metal-oxide-semiconductor connects described pulse signal, source electrode and drain electrode connect and connect described Section Point.

Further, in described frequency-photovoltaic conversion circuit, the described second parasitic circuit of eliminating has the 4th node, and the parasitic capacitance of described 4th node is equal with the parasitic capacitance of described Section Point.Described second parasitic circuit of eliminating comprises the 18 metal-oxide-semiconductor to the 24 metal-oxide-semiconductor, source electrode and the grid of described 18 metal-oxide-semiconductor connect, drain electrode connects described 4th node, the grid of described 20 metal-oxide-semiconductor connects pulse signal, drain electrode connects described 4th node, source electrode connects the source electrode of described 19 metal-oxide-semiconductor, the grid of described 19 metal-oxide-semiconductor connects pulse signal, source electrode and drain electrode connect and connect described reference voltage, the drain electrode of described 21 metal-oxide-semiconductor and the 22 metal-oxide-semiconductor all connects described 4th node, grid and source grounding, the drain electrode of described 23 metal-oxide-semiconductor connects described 4th node, grid connects pulse signal, source electrode connects the source electrode of described 24 metal-oxide-semiconductor, the grid of described 24 metal-oxide-semiconductor connects described pulse signal, source electrode and drain electrode connect and connect described Section Point.

Further, described frequency-photovoltaic conversion circuit also comprises pulse signal generating circuit, described pulse signal generating circuit produces the pulse signal of multiple control switch module according to described frequency signal, and described switching tube module comprises the first switching tube, the first charging valve, the first discharge tube and the first anti-crosstalk pipe;

Frequency signal, first described in the control termination of described first switching tube connects reference current described in termination, second and connects termination first node, described charge and discharge electric capacity one end connects described first node, other end ground connection, the control termination pulse signal of described first charging valve, two links connect between first node and output capacitance respectively, the control termination pulse signal of described first discharge tube, two links are ground connection and first node respectively, and control termination pulse signal, two links of described first anti-crosstalk pipe are connected between described first charging valve and output capacitance.

Further, described switch module also comprises the 3rd discharge tube, and the control termination pulse signal of described 3rd discharge tube, two to connect described in terminations between charge and discharge electric capacity to discharge further to described charging capacitor.

Further, described first switching tube, the first charging valve, the first discharge tube, the first anti-crosstalk pipe and the 3rd discharge tube receive different pulse signals, and described first switching tube, the first charging valve, the first discharge tube, the first anti-crosstalk pipe and the 3rd discharge tube are metal-oxide-semiconductor.

Further, described built-in oscillation circuit also comprises many times of frequency dividers, described many times of frequency dividers are arranged between described ring oscillator and frequency-photovoltaic conversion circuit, after described many times of frequency dividers carry out frequency division to described frequency signal, export described frequency-photovoltaic conversion circuit to, to make described frequency-photovoltaic conversion circuit stability work.

Further, when the stable output of described frequency signal, described frequency signal is:

wherein, M is the frequency division multiple of described many times of frequency dividers, and fout is the output frequency of described built-in oscillator, and Cc is the capacitance of the first charge and discharge electric capacity, and (Rp+Rn) produces the resistance value of the trimming resistors of circuit for basic current, K is proportionality coefficient.

Further, described many times of frequency dividers comprise the twice frequency divider of multiple cascade.

Further, described differential amplifier circuit comprises the second operational amplifier, resistance and electric capacity, one input of described second operational amplifier connects described reference voltage respectively, another input is connect between described feedback voltage by described resistance, exported ring oscillator described in termination, described electric capacity one end is connected between described first operational amplifier and described resistance, and the other end is connected between described first operational amplifier and described ring oscillator.

Further, described built-in oscillation circuit is arranged at the toy remote control equipment of frequency range at 27MHZ ~ 49MHZ.

Further, the wireless control apparatus of frequency range 315MHz or 433MHZ.

Further, frequency range is in the infrared remote control equipment of 38KHz.

In sum, built-in oscillation circuit of the present invention adopts negative feedback closed loop road form, utilize frequency-photovoltaic conversion mode, enable built-in oscillation circuit all integrated in the chips, eliminate and need the outside extra crystal oscillator arranged, save process costs, and be converted into feedback voltage by the frequency of oscillation produced by ring oscillator, and compare with reference voltage, then comparative result is fed back to the control end of ring oscillator, change the frequency of ring oscillator, thus by compensating the deviation of output frequency, decrease the impact of parasitic capacitance for frequency-photovoltaic conversion circuit that reference current connects input point, thus make loop stability export the operating frequency of Low Drift Temperature, and improve the frequency accuracy of oscillator.

Further, by eliminating circuit at described frequency-photovoltaic conversion circuit by introducing parasitism, avoid the introducing metal-oxide-semiconductor parasitic capacitance introduced at first node and Section Point place because of described frequency-photovoltaic conversion circuit, therefore in the process of discharge and recharge, reduce the sensitiveness to temperature, avoid the impact of parasitic capacitance on built-in oscillation circuit, improve the temperature characterisitic of frequency-photovoltaic conversion circuit, and then improve the temperature characterisitic of whole system.

Further, in described built-in oscillation circuit, described basic current is produced circuit and is controlled and high-order low level He Ne laser by the low level fine tuning of trimming resistors and a high position for the overriding mirror image circuit of multichannel, thus can by trimming the process deviation of a modification method to output frequency, the frequency reaching 0.1% trims precision, and can cover and wholely trim scope, disconnected joint.

Described built-in oscillation circuit, not only in technique, has higher stability when temperature deviation and supply voltage deviation, export a stable clock signal, and its reference frequency output is wide.

Accompanying drawing explanation

Fig. 1 is the structural representation of clock signal generating circuit in prior art.

Fig. 2 is the schematic diagram of built-in oscillation circuit in one embodiment of the invention.

Fig. 3 is the schematic diagram of built-in oscillation circuit in another embodiment of the present invention.

Fig. 4 .1 ~ Fig. 4 .3 is that in one embodiment of the invention, in built-in oscillation circuit, basic current produces the schematic diagram of circuit.

Fig. 5 .1 ~ Fig. 5 .3 is the schematic diagram of built-in oscillation circuit medium frequency-photovoltaic conversion circuit in the several embodiment of the present invention.

Fig. 6 is the signal graph of pulse signal generating circuit in the several embodiment medium frequency-photovoltaic conversion circuit of the present invention.

Fig. 7 is the schematic diagram that in one embodiment of the invention medium frequency-photovoltaic conversion circuit, the first parasitic capacitance eliminates circuit.

Fig. 8 is the schematic diagram that in one embodiment of the invention medium frequency-photovoltaic conversion circuit, the second parasitic capacitance eliminates circuit.

Fig. 9 is the schematic diagram of built-in oscillation circuit ring oscillator in one embodiment of the invention.

Figure 10 is the schematic diagram of many times of frequency dividers in built-in oscillation circuit in one embodiment of the invention.

Embodiment

For making content of the present invention clearly understandable, below in conjunction with Figure of description, content of the present invention is described further.Certain the present invention is not limited to this specific embodiment, and the general replacement known by those skilled in the art is also encompassed in protection scope of the present invention.

Secondly, the present invention's detailed statement that utilized schematic diagram to carry out, when describing example of the present invention in detail, for convenience of explanation, schematic diagram, should in this, as limitation of the invention not according to general ratio partial enlargement.

Fig. 2 is the schematic diagram of built-in oscillation circuit in one embodiment of the invention.As shown in Figure 2, built-in oscillation circuit of the present invention utilizes closed-loop structure, realizes stable output frequency by FEEDBACK CONTROL.Described built-in oscillation circuit comprises basic current and produces circuit 11 and ring oscillator 13, frequency-photovoltaic conversion circuit 15 and differential amplifier circuit 12.Its ring oscillator 13, frequency-photovoltaic conversion circuit 15 and differential amplifier circuit 12 form a negative feedback cor-rection loop.

In built-in oscillation circuit of the present invention, described basic current produces circuit 11 and is converted into reference current Iref with reference to voltage Vref, in described negative feedback cor-rection loop, described ring oscillator 13 produces frequency signal fout, described frequency-photovoltaic conversion circuit 15 receives described reference voltage Vref and frequency signal fout, and output feedack voltage Vout; Described differential amplifier circuit 12 receives and more described reference current Iref and feedback voltage V out, and produce the control voltage Vctr that is proportional to described reference current Iref and feedback voltage V out difference, carry out feedback compensation with the frequency controlling ring oscillator 13.In the course of work of built-in oscillation circuit, the output frequency of ring oscillator 13 be subject to temperature, the impact of the environment such as process deviation and supply voltage, such as when the temperature is changed, when assumed temperature rises, control voltage Vctr moment does not change, then the vibration output frequency of ring oscillator 13 declines, therefore the feedback voltage V out of frequency-photovoltaic conversion circuit 15 starts to reduce, and reference voltage Vref remains unchanged, then the control voltage Vctr of differential amplifier circuit 12 reduces, the output frequency fout of ring oscillator 13 increases with the minimizing of control voltage Vctr subsequently, the feedback voltage V out of frequency-photovoltaic conversion circuit 15 increases thereupon, then negative-feedback regu-lation carries out always, until feedback voltage V out is equal with reference voltage Vref, namely till the loop of built-in oscillation circuit is stablized again, equally, upon a drop in temperature, also there is identical negative-feedback regu-lation process, till the loop of built-in oscillation circuit is stablized again.

Fig. 3 is the schematic diagram of built-in oscillation circuit in another embodiment of the present invention, as shown in Figure 3, described built-in oscillation circuit can also comprise voltage stabilizing generator 16 and many times of frequency dividers 14, described voltage stabilizing generator 16 receives an external power source VDD, and VDD is converted into supply voltage VDDA and the reference voltage Vref of stable output, described supply voltage VDDA produces circuit 11 for basic current in described built-in oscillation circuit and negative feedback cor-rection loop provides stable supply voltage, thus ensures the steady operation of built-in oscillation circuit.Described many times of frequency dividers 14 carry out frequency division for producing frequency signal fout to described ring oscillator 13, produce the frequency signal fb after frequency division to described frequency-photovoltaic conversion circuit 15, increase and described many times of frequency dividers 14 are set can make described frequency-photovoltaic conversion circuit 15 can steady operation.

Fig. 4 .1 is that in one embodiment of the invention, in built-in oscillation circuit, basic current produces the schematic diagram of circuit.In preferred embodiment, the overriding mirror image circuit of multichannel can adopt common-source common-gate current mirror structure, thus further reduces the temperature coefficient of image current, makes the output of reference current Iref be proportional to electric current I 1, and temperature independent.

As shown in Fig. 4 .1, described mirror image circuit is the overriding mirror image circuit of multichannel, described basic current produces circuit 11 and comprises the first operational amplifier A 1, first amplifier tube M1 (the first amplifier tube is NMOS tube), trimming resistors (Rp+Rn) and mirror image circuit, the input of described first operational amplifier A 1 connects first link of reference voltage Vref and the first amplifier tube M1 respectively, the control end of the first amplifier tube M1 described in the output termination of described first operational amplifier A 1, first link of described trimming resistors (Rp+Rn) two ends difference ground connection and described first amplifier tube M1, second of described first amplifier tube M1 connects supply voltage VDDA described in termination, described mirror image circuit comprises the first mirror image efferent duct Mp1, the control end of the first amplifier tube M1 described in the control termination of described first mirror image efferent duct Mp1, first link of described first mirror image efferent duct Mp1 exports described reference current Iref, described first mirror image efferent duct Mp1 second connects supply voltage VDDA described in termination.Wherein said first operational amplifier A 1 receives a reference voltage Vref, after described trimming resistors (Rp+Rn) trims, export an intermediate current I1 by the first amplifier tube A1, and described intermediate current I1 exports reference current Iref through described mirror image circuit.

Fig. 4 .2 is that in another embodiment of the present invention, in built-in oscillation circuit, basic current produces the schematic diagram of circuit.As shown in Fig. 4 .2, described basic current produces circuit 11 and comprises the first operational amplifier A 1, first amplifier tube M1, trimming resistors (Rp+Rn) and mirror image circuit, mirror image circuit comprises the first mirror image input pipe M3 in an embodiment, second mirror image input pipe M2, first mirror image efferent duct Mn1 and the second mirror image efferent duct Mp1, second link of the first amplifier tube M1 described in the control termination of described first mirror image input pipe M3, first of described first mirror image input pipe M3 connects second link of the second mirror image input pipe M2 described in termination, second of described first mirror image input pipe M3 connects termination one supply voltage VDDA, second of described second mirror image input pipe M2 connects second link of the first amplifier tube M1 described in termination, the control end of the first mirror image input M3 described in the control termination of described first mirror image efferent duct Mn1, first of described first mirror image efferent duct Mn1 connects second link of the second mirror image efferent duct Mp1 described in termination, second of described first mirror image efferent duct Mn1 connects supply voltage VDDA described in termination, the control end of the second mirror image input pipe M2 described in the control termination of described second mirror image efferent duct Mp1, first link of described second mirror image efferent duct Mp1 exports described reference current Ib, second link of described second mirror image efferent duct Mp1 is connected with first link of one first mirror image efferent duct Mn1.

Fig. 4 .3 is that in another embodiment of the present invention, in built-in oscillation circuit, basic current produces the schematic diagram of circuit.As shown in Fig. 4 .3, in preferred embodiment, described mirror image circuit is the overriding mirror image circuit of multichannel, described basic current produces circuit 11 and comprises the first operational amplifier A 1, first amplifier tube M1 (the first amplifier tube is NMOS tube), trimming resistors (Rp+Rn) and mirror image circuit, mirror image circuit adopts the overriding mirror image circuit of multichannel in an embodiment, comprise the first mirror image input pipe M3, second mirror image input pipe M2, multiple first mirror image efferent duct Mn1 ~ Mnn and multiple second mirror image efferent duct Mp1 ~ Mpn, second link of the first amplifier tube M1 described in the control termination of described first mirror image input pipe M3, first of described first mirror image input pipe M3 connects second link of the second mirror image input pipe M2 described in termination, second of described first mirror image input pipe M3 connects termination one supply voltage VDDA, second of described second mirror image input pipe M2 connects second link of the first amplifier tube M1 described in termination, the control end of first mirror image efferent duct Mn1 ~ Mnn described in each all connects the control end of described first mirror image input pipe M3, second of first mirror image efferent duct Mn1 ~ Mnn described in each connects supply voltage VDDA described in termination, the control end of second mirror image efferent duct Mp1 ~ Mpn described in each all connects the control end of described second mirror image input pipe M2, the described reference current Ib of rear output that is connected of described second mirror image efferent duct, described in each, second link of second mirror image efferent duct Mp1 ~ Mpn is connected with first link of one first mirror image efferent duct Mn1 ~ Mnn.Described basic current circuit for generating 11 selects 6 trimming resistors, the 6 overriding image current modules in road and two-way high frequency low frequency to select image current module to trim, and can trim the frequency shift (FS) that process deviation brings, reach output frequency permissible accuracy.

Particularly, in actual process production process, the temperature deviation of the output frequency fout of described built-in pierce circuit gets main temperature characterisitic of determining in the later resistance of loop-locking and electric capacity.In actual process, the temperature coefficient of electric capacity is at every degree Celsius 10 ^-6secondary magnitude, and the temperature coefficient of single resistance is 10 ^-3secondary magnitude, so temperature coefficient determines primarily of resistance-temperature characteristic.In order to reach deviation within-20 DEG C ~ 85 DEG C scopes 1%, need to compensate temperature coefficient of resistance, therefore trimming resistors selects the resistance Rp of positive temperature coefficient and the resistance Rn series complementary of negative temperature coefficient, makes trimming resistors by the impact of temperature.

Producing circuit below in conjunction with the basic current shown in Fig. 4 .3 to be described in detail, because resistance and electric capacity exist certain process deviation, therefore in order to reach the frequency required for us, needing to trim process deviation.The process deviation of described built-in oscillation circuit output frequency can be revised by trimming position, realize 0.1% trim precision.For the frequency reaching 0.1% trims precision, the frequency deviation brought of covering process voltage temperature deviation, supposes that frequency deviation is ± 50%, then at least needs log again ₂ ⁽¹⁰⁰⁰⁾=10bit control bit, add and select frequency range (such as: 27M, 40M or 49M or 315M, 433M), in order to both can cover the scope of trimming, need to increase 2bit again to save to ensure that adjacent fine tuning scope overlaps each other to break, therefore need the control bit at least requiring 12bit.If single control adjustable resistance R or single control current mirror ratio, then chip area all will be quite large; If single employing controls adjustable resistance, so need 2 ¹⁰=1024 right resistance, chip area equally can be quite large, for electric current too.Therefore, built-in oscillation circuit of the present invention adopts the method that a current mirror high position controls and the fine tuning of adjustable resistance low level combines to save chip area, only needs adjustable resistance 2 ⁶=64 is right, image current 2 ⁶=64 is right, and total area is much smaller than 1024 couple of single regulative mode.

Shown in composition graphs 3, described built-in oscillation circuit comprises M the first mirror image efferent duct, described basic current produces circuit and receives a multidigit control signal, described multidigit control signal comprises He Ne laser position, mirror image circuit regulates position and resistance adjustment position, described He Ne laser position controls N number of first mirror image efferent duct (Mn1 and Mn2) and selects to realize frequency range with the ratio value of described first mirror image input pipe M3, described mirror image circuit regulates position to control the ratio value of all the other L the first mirror image efferent ducts (Mn3 ~ Mnn) and described first mirror image input pipe M3 to realize coarse adjustment in frequency range, described resistance adjustment position controls the resistance value of described trimming resistors (Rp+Rn) to realize accurate adjustment in frequency range.Wherein, N, L and M are positive integer, and described N number of first mirror image efferent duct and L the first mirror image efferent duct are the first different mirror image efferent ducts, and N+L=M.In the present embodiment, be that example is described with M=8, N=2.One encoder 18 produces to described basic current the control signal D<13:0> that circuit produces 14, and wherein D<13:12> is He Ne laser position (00,01,10,11); D<11:6> is that mirror image circuit regulates position; D<5:0> is resistance adjustment position; After determining the frequency that will export, select the value of D<13:12>, in order to the frequency deviation (suppose ± 50%) wanting covering process voltage temperature deviation to bring, the frequency reaching 0.1% again trims precision.Described circuitous resistance realize 0.1% trim precision, realize frequency coarse adjustment at image current place and reach the precision being about 0.64%.Suppose to realize rate-adaptive pacemaker fout, so the resistance value of multichannel trimming resistors (Rp+Rn) is R, then the adjustable range of (Rp+Rn) is

$R+(D0*2^0+D1*2^1+...+2^5*D5)*\frac{R}{1000},$

Resistance adjustment position D<5:0>=000000---111111, the scope that frequency can reduce is 0.1%-6.4%, realizes accurate adjustment.The frequency deviation of wanting covering process voltage temperature deviation to bring (suppose ± 50%), the precision of image current is for being less than 6.4%, so 100%/6.4%=15.6<24, can know and at least need 4 overriding positions, adopt 6 overriding circuit to make frequency coverage enough large here.Suppose base image electric current I ref=K*I1, add the size of gross adjustment currents, then image current Iref is:

$\mathrm{Ib}=K*I1+[(D6*2^0+D7*2^1+...+2^5*D11)*\frac{1}{64}*K*I1],$

During mirror image circuit adjustment position D<11:6>=100000, frequency is the centre frequency of requirement, then D<11:6>=111111 is frequency that is large and centre frequency 50%, and D<11:6>=000000 is the frequency being less than centre frequency 50%.So just can covering total process deviation, rate-adaptive pacemaker can be realized through trimming.

He Ne laser position (D<13:12>) control ratio realizes large electric current and exports, and realizes the frequency shift that range is larger.The frequency deviation of wanting covering process voltage temperature deviation to bring (suppose ± 50%), so total frequency deviation 100%/212=0.024% trims precision much smaller than the frequency of 0.1%.So just can covering total process deviation, rate-adaptive pacemaker can be realized through trimming.

Wherein, trimming resistors (Rp+Rn) represents that the resistance of positive temperature coefficient and the resistance of negative temperature coefficient are added, and when designing suitable, temperature coefficient is cancelled out each other.First operational amplifier A 1 produces corresponding electric current I 1 according to reference voltage Vref, the voltage Vbp of the control end of the second mirror image input pipe M2 is in order to ensure that the second mirror image input pipe M2 and the first mirror image input pipe M3 is operated in saturation region, first operational amplifier A 1, first amplifier tube M1 forms negative feedback, in order to ensure that the voltage of P point in Fig. 4 .3 is reference voltage Vref, the secondth mirror image input pipe M2 and the first mirror image input pipe M3 and multiple first mirror image efferent duct Mn1 ~ Mnn and multiple second mirror image efferent duct Mp1 ~ Mpn is mirror.

Basic current can be obtained by upper analysis to produce the intermediate current I1 that produces of circuit 11 and be: I1=Vref/ (Rp+Rn);

Can be obtained by mirror image circuit: Iref=K*I1;

Wherein, Vref represents described reference voltage, the resistance value that (Rp+Rn) is trimming resistors, wherein Rp is the resistance of the positive temperature coefficient of trimming resistors, Rn represents the resistance of the negative temperature coefficient of trimming resistors, and the value of reference current Iref is directly proportional to I1, and K is proportionality coefficient; Then described basic current produces the reference current formula (1) that circuit 11 produces:

Iref＝K*Vref/(Rp+Rn)------(1)

Fig. 5 .1 is the schematic diagram of built-in oscillation circuit medium frequency-photovoltaic conversion circuit in one embodiment of the invention.As shown in Fig. 5 .1, described frequency-photovoltaic conversion circuit 15 comprises switching tube module, charge and discharge electric capacity and output capacitance C1, described switching tube module receives the frequency signal fb after described reference current Iref and frequency signal fout or frequency division, and under the control of frequency signal fb after described frequency signal fout or frequency division, carry out described reference current Iref is charged to described charge and discharge electric capacity and carry out between charge and discharge electric capacity and output capacitance C1 the process that electric charge is redistributed and discharged to described charge and discharge electric capacity, to make described output capacitance output feedack voltage.

Fig. 5 .1 ~ Fig. 5 .3 is the schematic diagram of built-in oscillation circuit medium frequency-photovoltaic conversion circuit in an embodiment.As shown in Fig. 5 .1, in the present embodiment, described frequency-photovoltaic conversion circuit 15 receives the fractional frequency signal fb of the frequency signal fout that many times of frequency dividers 14 as shown in Figure 3 export, described frequency-photovoltaic conversion circuit 15 can be made more stably to work, and the frequency signal fout that certain described frequency-photovoltaic conversion circuit 15 directly receives the output of described ring oscillator can realize the course of work equally.Described frequency-photovoltaic conversion circuit comprises switching tube module, charge and discharge electric capacity and output capacitance, described switching tube module receives the fractional frequency signal fb of described reference current Iref and frequency signal fout, and under the control of the fractional frequency signal fb of described frequency signal fout, carry out described reference current Iref is charged to described charge and discharge electric capacity and carry out between charge and discharge electric capacity and output capacitance the process that electric charge is redistributed and discharged to described charge and discharge electric capacity, to make described output capacitance output feedack voltage.Described frequency-photovoltaic conversion circuit also comprises pulse signal generating circuit and parasitic capacitance eliminates circuit.Described parasitism elimination circuit comprises the first parasitic elimination circuit and the second parasitism eliminates circuit, described charge and discharge electric capacity comprises the first charge and discharge electric capacity Cc and the second charge and discharge electric capacity Cc1, described switching tube module comprises the first switching tube M11, first charging valve M19, first discharge tube M13, second switch pipe M12, second charging valve M14, second discharge tube M16, first anti-crosstalk pipe 20, second anti-crosstalk pipe 18, wherein the first switching tube M11, first charging valve M19, first discharge tube M13, second switch pipe M12, second charging valve M14, second discharge tube M16, first anti-crosstalk pipe 20, second anti-crosstalk pipe 18 is metal-oxide-semiconductor, described pulse signal generating circuit produces the pulse signal of multiple control switch module according to described frequency signal, described pulse signal generating circuit produces multiple pulse signal according to the fractional frequency signal fb of described frequency signal and the inversion signal fb-of fractional frequency signal, comprise eight pulse signals, for generation of control first charge and discharge electric capacity Cc, the pulse signal of the second charge and discharge electric capacity Cc1, Fig. 6 is the signal graph of pulse signal generating circuit in one embodiment of the invention medium frequency-photovoltaic conversion circuit, as shown in Figure 6, first to fourth pulse signal CLK1, CLK2, CLK3, the CLK11 of the 5th to the 8th pulse signal of CLK4 and successively difference half period corresponding to the phase place of first to fourth pulse signal, CLK21, CLK31, CLK41.Wherein, the pulse signal width summation of described first to fourth pulse signal is less than the half period of incoming frequency, and the pulse signal width summation of described 5th to the 8th pulse signal is less than the half period of incoming frequency.Frequency signal fb described in the control termination of described first switching tube M11, first connects reference current Iref described in termination, second connects termination first node P1, the inversion signal fb-of frequency signal described in the control termination of described second switch pipe M12, first connects reference current Iref described in termination, second connects termination Section Point P2, first node P1 described in described first charge and discharge electric capacity Cc mono-termination, other end ground connection, Section Point P2 described in described second charge and discharge electric capacity Cc1 mono-termination, other end ground connection, the control termination pulse signal CLK1 of described first charging valve M19, two links connect between first node P1 and output capacitance C1 respectively, the control termination pulse signal CLK11-of described second charging valve M17, two links connect between Section Point P2 and output capacitance C1 respectively, the control termination pulse signal CLK2 of described first discharge tube M13, two links are ground connection and first node P1 respectively, the control termination pulse signal CLK21 of described second discharge tube M14, two links are ground connection and Section Point P2 respectively, described first parasitic capacitance is eliminated circuit input end and is connect multiple described pulse signal, export first node P1 described in termination, described second parasitic circuit input end of eliminating connects multiple described pulse signal, export Section Point P2 described in termination, the control termination pulse signal CLK1-of described first anti-crosstalk pipe M20, two links are connected between described first charging valve M19 and output capacitance C1, the control termination pulse signal CLK11 of described second anti-crosstalk pipe M18, two links are connected between the second charging valve Cc1 and output capacitance C1.In addition, described switch module also comprises the 3rd discharge tube M15 and the 4th discharge tube M16, the control termination pulse signal CLK3 of described 3rd discharge tube M15, described in two connection terminations between the first charge and discharge electric capacity Cc and ground, the control termination pulse signal CLK31 of described 4th discharge tube M16, described in two connection terminations between the second charge and discharge electric capacity Cc1, described 3rd discharge tube M15 is used for discharging to described first charge and discharge electric capacity further, described 4th discharge tube M16 is used for discharging to described second charge and discharge electric capacity further, described 3rd discharge tube M15 and described 4th discharge tube M16 is metal-oxide-semiconductor.

Fig. 7 is the schematic diagram that in one embodiment of the invention medium frequency-photovoltaic conversion circuit, the first parasitic capacitance eliminates circuit.As shown in Figure 7, in a preferred embodiment, described first parasitic capacitance eliminates the parasitic capacitance of the 3rd node P3 and the parasitic capacitance of described first node P1 in circuit, its structure can comprise the 11 metal-oxide-semiconductor M21 to the 17 metal-oxide-semiconductor M27, the source electrode of described 11 metal-oxide-semiconductor M21 and grid connect and meet described supply voltage VDDA, drain electrode meets described 3rd node P3, the grid of described 13 metal-oxide-semiconductor M23 meets the first pulse signal CLK2, drain electrode meets described 3rd node P3, source electrode connects the source electrode of described 12 metal-oxide-semiconductor M22, the grid of described 12 metal-oxide-semiconductor M22 meets the inversion signal CLK2-of the first pulse signal, source electrode and drain electrode connect and connect described reference voltage Vref, the drain electrode of described 14 metal-oxide-semiconductor M24 and the 15 metal-oxide-semiconductor M25 all meets described 3rd node P3, grid and source grounding, the drain electrode of described 16 metal-oxide-semiconductor M26 meets described 3rd node P3, grid meets the 4th pulse signal CLK4, source electrode connects the source electrode of described 17 metal-oxide-semiconductor M27, the grid of described 17 metal-oxide-semiconductor M27 meets the inversion signal CLK4-of described 4th pulse signal, source electrode and drain electrode connect and meet described Section Point P2.Wherein, the parasitic capacitance of the 11 metal-oxide-semiconductor M21 is corresponding identical with the parasitic capacitance of the drain electrode of the first switching tube M1, the second discharge tube M3 that 14 metal-oxide-semiconductor M24 and the 15 metal-oxide-semiconductor M25 and same first node P1 point connect to ground is corresponding identical with the parasitic capacitance of the first discharge tube M5, the parasitic capacitance of the 12 metal-oxide-semiconductor M22 and the first charging valve M19 between the 13 metal-oxide-semiconductor M23 with same first node P1 to feedback voltage V out is corresponding identical, and the 16 metal-oxide-semiconductor M26 and the 17 metal-oxide-semiconductor M27 is switch control terminal.

In described frequency-photovoltaic conversion circuit, the described second parasitic circuit of eliminating has the 4th node P4, and the parasitic capacitance of described 4th node P4 is equal with the parasitic capacitance of described Section Point P2.Fig. 8 is the schematic diagram that in one embodiment of the invention medium frequency-photovoltaic conversion circuit, the second parasitic capacitance eliminates circuit.As shown in Figure 8, described second parasitic circuit of eliminating comprises the 18 metal-oxide-semiconductor M28 to the 24 metal-oxide-semiconductor M34, the source electrode of described 18 metal-oxide-semiconductor M28 and grid connect and meet described supply voltage VDDA, drain electrode meets described 4th node P4, the grid of described 20 metal-oxide-semiconductor M30 meets the first pulse signal CLK21, drain electrode meets described 4th node P4, source electrode connects the source electrode of described 19 metal-oxide-semiconductor M29, the grid of described 19 metal-oxide-semiconductor M29 meets the inversion signal CLK21-of the 5th pulse signal, source electrode and drain electrode connect and connect described reference voltage Vref, the drain electrode of described 21 metal-oxide-semiconductor M31 and the 22 metal-oxide-semiconductor M32 all meets described 4th node P4, grid and source grounding GND, the drain electrode of described 23 metal-oxide-semiconductor M33 meets described 4th node P4, grid meets the 8th pulse signal CLK41, source electrode connects the source electrode of described 24 metal-oxide-semiconductor M34, the grid of described 24 metal-oxide-semiconductor M34 meets the inversion signal CLK41-of described 4th pulse signal, source electrode and drain electrode connect and meet described Section Point P2.

Described frequency-photovoltaic conversion circuit adopts differential configuration, decreases reference current Iref and connects the parasitic capacitance of input node P point for the impact of frequency-photovoltaic conversion circuit, improve the frequency accuracy of oscillator, simultaneously, because there is more metal-oxide-semiconductor in described first node P1 and Section Point P2, the parasitic capacitance of metal-oxide-semiconductor can be introduced, suppose that the capacitance size of first node P1 and Section Point is Cp1, the sensitiveness of parasitic capacitance to temperature is larger, therefore in the process of the first charge and discharge electric capacity Cc and the second charge and discharge electric capacity Cc1 discharge and recharge, the parasitic capacitance of metal-oxide-semiconductor can cause the temperature characterisitic of whole frequency-photovoltaic conversion circuit to be deteriorated, therefore prior art, frequency of the present invention-photovoltaic conversion circuit is by introducing parasitic elimination circuit, avoid the impact of parasitic capacitance on built-in oscillation circuit, and then improve the temperature characterisitic of whole system.

In addition, frequency of the present invention-photovoltaic conversion circuit can also adopt the structure as shown in Fig. 5 .2 and Fig. 5 .3.As shown in Fig. 5 .2, in described frequency-photovoltaic conversion circuit, described charge and discharge electric capacity comprises the first charge and discharge electric capacity Cc, described switching tube module comprises the first switching tube M11, the first charging valve M19, the first discharge tube M13, the first anti-crosstalk pipe 20 and the first ground pipe M121, first charge and discharge electric capacity Cc, described switching tube module comprises the first switching tube M11, the first charging valve M19, the first discharge tube M13, the first anti-crosstalk pipe 20 and the first ground pipe M121 and is metal-oxide-semiconductor; Described pulse signal generating circuit produces the pulse signal of multiple control switch module according to described frequency signal, described pulse signal generating circuit produces multiple pulse signal according to the fractional frequency signal fb of described frequency signal and the inversion signal fb-of fractional frequency signal, for generation of the pulse signal of control first charge and discharge electric capacity Cc, such as first to the 3rd pulse signal CLK1, CLK2, CLK3.Wherein, the summation of the width of described pulse signal is less than the half period of incoming frequency.Frequency signal fb described in the control termination of described first switching tube M11, first connects reference current Iref described in termination, second connects termination first node P1, first node P1 described in described first charge and discharge electric capacity Cc mono-termination, other end ground connection, the control termination pulse signal CLK1 of described first charging valve M19, two links connect between first node P1 and output capacitance C1 respectively, the control termination pulse signal CLK2 of described first discharge tube M13, two links are ground connection and first node P1 respectively, the control termination pulse signal CLK1-of described first anti-crosstalk pipe M20, two links are connected between described first charging valve M19 and output capacitance C1, first ground pipe M121 control end receives the fractional frequency signal fb of described frequency signal, first connects reference current described in termination, second link Iref ground connection.First charging valve, the first discharge tube, the first anti-crosstalk pipe and the first ground pipe are metal-oxide-semiconductor.As shown in Fig. 5 .3, on the basis of the described frequency-photovoltaic conversion circuit shown in Fig. 5 .2, described frequency-photovoltaic conversion circuit also comprises the 3rd discharge tube M15, the control termination pulse signal CLK2 of described 3rd discharge tube M15, two to connect described in terminations between the first charge and discharge electric capacity Cc and ground, for discharging to described first charge and discharge electric capacity further, described 3rd discharge tube M15 is metal-oxide-semiconductor.

Below for the preferably described frequency-photovoltaic conversion circuit structure shown in Fig. 5 .1, the course of work of described frequency-photovoltaic conversion circuit is described, specifically comprises four-stage: charging stage, electric charge are redistributed, discharge regime and pre-charge process.For convenience of description, in description, described frequency-photovoltaic conversion circuit is divided into the first conversion circuit 151 and the second conversion circuit 152 as shown in Fig. 5 .1, when fractional frequency signal fb is low level, when the inversion signal fb-of fractional frequency signal is high level, first conversion circuit 151 is in the charging stage, and the second conversion circuit 152 is in that electric charge is redistributed, discharge regime and pre-charge process.

For the course of work of the first conversion circuit 151 of frequency-photovoltaic conversion circuit.In the charging stage: when fractional frequency signal fb is low level, first switching tube M11 conducting, reference current Iref charges to the first charge and discharge electric capacity Cc, the parasitic capacitance summation that first node P1 point exists is that Cp1 (comprises the first discharge tube M13, 3rd discharge tube M15, the parasitic capacitance that first charging valve M19 and the first switching tube M1 produces at first node P1), so first node P1 point exist electric capacity and be (Cc+Cp1), therefore while the first charge and discharge electric capacity Cc is charged, also can charge to the parasitic capacitance Cp1 of first node P1.

When fractional frequency signal fb transfers high level to, charging complete, the first switching tube M1 ends, so the voltage Vp1 of the level at first node P1 place after charge cycle terminates is formula (2);

$\mathrm{Vp}1=\frac{\mathrm{Iref}*\mathrm{Tb}/2}{(\mathrm{Cc}+\mathrm{Cp}1)}=\frac{\mathrm{Iref}}{2*\mathrm{fb}*(\mathrm{Cc}+\mathrm{Cp}1)}---\left(2\right)$

In formula, Iref is reference current, and Tb is the cycle of the fractional frequency signal fb of frequency signal, and Cc is the first charge and discharge capacitance, and Cp1 is the parasitic capacitance of first node.

Redistribute in the stage at electric charge: before the next charging stage arrives, pulse signal CLK1 enters high level, make the first charging valve M19 conducting, the electric charge that first charge and discharge electric capacity Cc fills is redistributed between the first charge and discharge electric capacity Cc and output capacitance C1, wherein, the Main Function of the first anti-crosstalk pipe M20 is the Charge injection effect in order to reduce the first charging valve M19, suppresses clock feed-through effect.

In discharge regime: the first pulse signal CLK1 triggers generation second pulse signal CLK2 and enters high level, make the first discharge tube M13 conducting, P1 point charge is discharged by the first discharge tube M13, in order to the first charge and discharge electric capacity Cc is thoroughly discharged, pulse signal CLK2 start pulse signal CLK3, thus the residual charge of P1 point is bled off again by the 3rd discharge tube M15, the electric charge of P1 point reduces to zero afterwards.

In pre-charging stage: the 3rd pulse signal CLK3 triggers and produces pulse signal CLK4, first parasitic capacitance is eliminated P3 in circuit, when pulse signal CLK2 is high level, P point is pre-charged to reference voltage Vref, the parasitic capacitance of P3 point equals the parasitic capacitance of P1 point, be Cp1, then the electric charge of P3 point is Vref*Cp1.Pulse signal CLK4 makes the 16 charge and discharge metal-oxide-semiconductor M16 conducting, and the electric charge of P3 point is redistributed between Cc and parasitic capacitance by the 16 charge and discharge metal-oxide-semiconductor M26, obtains the low-voltage Vcp1 that parasitic capacitance produces:

$\mathrm{Vcp}1=\frac{\mathrm{Vref}*\mathrm{Cp}1}{\mathrm{Cp}1+\mathrm{Cc}}---\left(3\right)$

So, when next pulse signal low level arrives, the voltage of P1 point is charged to Vcp1, and like this, under identical frequency, the voltage of P1 point after at every turn completing charging is:

$\mathrm{Vp}1=\frac{\mathrm{Iref}}{2*\mathrm{fb}*(\mathrm{Cc}+\mathrm{Cp}1)}+\frac{\mathrm{Vref}*\mathrm{Cp}1}{(\mathrm{Cc}+\mathrm{Cp}1)}---\left(4\right)$

Equally, the second conversion circuit 151 has the identical course of work, also can obtain, then the voltage of P2 point after each charging complete is Vp2:

$\mathrm{Vp}2=\frac{\mathrm{Iref}}{2\mathrm{fb}*(\mathrm{Cc}1+\mathrm{Cp}2)}+\frac{\mathrm{Vref}*\mathrm{Cp}2}{(\mathrm{Cc}1+\mathrm{Cp}2)}---\left(5\right)$

Because the first charge and discharge electric capacity Cc is identical with the electric capacity of the second charge and discharge electric capacity Cc1, therefore P1 point is identical with the parasitic capacitance of P2 point, and Vp1 and Vp2 is the signal that two phase places are contrary.

Above-mentioned charging-Charger transfer-discharge process-precharge is through M all after date, and M is positive integer, the feedback voltage V out that frequency-photovoltaic conversion circuit exports:

$\mathrm{Vout}=\frac{1}{2}\mathrm{Vp}1+\frac{1}{2^2}\mathrm{Vp}1+\frac{1}{2^3}\mathrm{Vp}1+...+\frac{1}{2^M}\mathrm{Vp}1---\left(6\right)$ $=\mathrm{Vp}1(1-\frac{1}{2^M})$

In addition, after first node P1 and Section Point P2 charges, the worst error of output level and its voltage is:

$\mathrm{\&Delta;Ve}=\frac{1}{2^M}\mathrm{Vp}1$

Therefore, when M is enough large, namely can thinks and finally realize Vout=Vp1, so then feedback voltage V out is as shown in formula (7):

$\mathrm{Vout}=\mathrm{Vp}1=\frac{\mathrm{Iref}}{2\mathrm{fb}*(\mathrm{Cc}+\mathrm{Cp}1)}+\frac{\mathrm{Vref}*\mathrm{Cp}1}{(\mathrm{Cc}+\mathrm{Cp}1)}---\left(7\right)$

When the gain of differential amplifier circuit 12 is enough large, during loop stability, then Vout=Vref.

Can be obtained by formula (1), when prior art does not eliminate parasitic capacitance,

$\mathrm{Vref}=\mathrm{Vout}$

$=\frac{\mathrm{Iref}}{2*\mathrm{fb}*(\mathrm{Cc}+\mathrm{Cp}1)}$

Can be obtained by formula (1), (2),

namely the rate-adaptive pacemaker of built-in oscillation circuit is correlated with resistance (Rp+Pn), the first charge and discharge electric capacity Cc and parasitic capacitance Cp1, the temperature characterisitic of output frequency is correlated with, not only relevant with electric capacity Cc with resistance (Rp+Pn), and by the impact of temperature characterisitic of parasitic capacitance Cp1, therefore less stable.

Compared to prior art, after built-in oscillation circuit of the present invention adds the first parasitic capacitance elimination circuit and the second parasitic capacitance elimination circuit,

$\mathrm{Vref}=\mathrm{Vout}$

$=\frac{\mathrm{Iref}}{2\mathrm{fb}*(\mathrm{Cc}+\mathrm{Cp}1)}+\frac{\mathrm{Vref}*\mathrm{Cp}1}{(\mathrm{Cc}+\mathrm{Cp}1)}---\left(9\right)$

Formula (4) can be obtained fom the above equation

$\mathrm{Vref}=\frac{\mathrm{Iref}}{2\mathrm{fb}*\mathrm{Cc}}---\left(10\right)$

By formula (1) (10), can obtain

$\mathrm{fb}=\frac{K}{2*(\mathrm{Rp}+\mathrm{Rn})*\mathrm{Cc}},$

Fout=M*fb again, then output frequency

when described frequency-photovoltaic conversion circuit 15 receive be the fractional frequency signal of many times of frequency dividers 14 time, then M is the frequency division multiple of described many times of frequency dividers, when described frequency-photovoltaic conversion circuit 15 directly receives the frequency signal of described ring oscillator 13, then M=1 in formula, namely $\mathrm{fout}=\frac{K}{\mathrm{Cc}*(\mathrm{Rp}+\mathrm{Rn})}.$

Analyze visible thus, the output frequency fout of built-in oscillation circuit of the present invention and mains voltage variations have nothing to do, and temperature voltage technique (PVT) characteristic of output frequency fout is determined by the PVT characteristic of resistance (Rp+Pn) and electric capacity Cc.Therefore, if resistance (Rp+Rn) and Cc have less temperature coefficient, then the output signal frequency of ring oscillator VCO also will have less temperature coefficient.

Fig. 9 is the schematic diagram of built-in oscillation circuit ring oscillator in one embodiment of the invention.As shown in Figure 9, described ring oscillator comprises multistage voltage controlled oscillator (VCO), form the difference channel of cascade, in the present embodiment, comprise 4 grades of voltage controlled oscillators and form 4 grades of cascaded differential circuit, described control voltage Vctr controls the output frequency fout that 4 voltage controlled oscillators control whole ring oscillator.Ring oscillator 13 of the present invention is convenient to integrated ring oscillator, and the controlled voltage Vctr of its output frequency fout controls, along with the minimizing frequency of control voltage Vctr increases.Thus by selection ring oscillator structure with by suitable parameter designing, ring oscillator 13 has possibility at different temperatures and is operated in identical frequency.Wherein, the delay unit of ring oscillator 13 adopts positive feedback technique to carry out the time of delay of control lag unit, thus changes the output frequency of circuit.

Figure 10 is the schematic diagram of many times of frequency dividers in built-in oscillation circuit in one embodiment of the invention.As shown in Figure 10, the output frequency fout of ring oscillator 13 is carried out frequency division by described many times of frequency dividers 12, and to produce duty ratio be frequency signal fb after the output frequency division of 50%.Under specific technique, obtain higher output frequency, the circuit performance of the charge and discharge capacitor charge and discharge in frequency-photovoltaic conversion circuit 15 can be affected, so by increasing many times of frequency dividers 12 in negative feedback cor-rection loop, after frequency signal fb after making the switch operating frequency of the charge and discharge electric capacity in frequency-photovoltaic conversion circuit 15 be operated in frequency division, thus ensure the performance of frequency-photovoltaic conversion circuit 15.In the present embodiment, many times of frequency dividers 12 comprise the twice frequency divider of multiple cascade, such as, comprise n 2 frequency divider, then M=2 ⁿ, wherein M is the frequency division multiple of many times of frequency dividers 12.Wherein, described twice frequency divider can by a d type flip flop and an inverter.

In addition, shown in composition graphs 3, described differential amplifier circuit 12 comprises the first operational amplifier A 1, resistance R1 and electric capacity C0, and described resistance R1 and electric capacity C0 is mainly used in removing coupled noise, and improves the stability of loop.The positive input of the first operational amplifier A 1 connects reference voltage Vref, the one termination feedback voltage V out of resistance R1, the negative-phase input of another termination first operational amplifier A 1 and one end of electric capacity C0, the output of another termination first operational amplifier A 1 of electric capacity C0.The output of the first operational amplifier A 1 exports the input of control voltage Vctr to ring oscillator 13.

In addition, crystal oscillator of the prior art produces circuit to be needed to arrange crystal oscillator outside sheet, and utilizes crystal oscillator to produce vibration, and therefore cost is higher, although and the frequency accuracy that the crystal oscillator of prior art produces circuit can reach 1ppm ~ 100ppm, its frequency range can only at 1KHz ~ 100MHz.Compared to prior art, built-in oscillator of the present invention can all be arranged on sheet, ring oscillator is adopted to control to produce frequency, therefore it has saved cost greatly, and greatly can improve frequency range by arranging many times of frequency dividers, reach 10KHz-450MHz and be widely used in various product such as, frequency range is at the toy remote control equipment of 27MHZ ~ 40MHZ, and the wireless control apparatus of frequency range 315MHz or 433MHZ and frequency range are in the equipment such as infrared remote control equipment of 38KHz.

In sum, built-in oscillation circuit of the present invention adopts negative feedback closed loop road form, utilize frequency-photovoltaic conversion mode, enable built-in oscillation circuit all integrated in the chips, eliminate and need the outside extra crystal oscillator arranged, save process costs, and be converted into feedback voltage by the frequency of oscillation produced by ring oscillator, and compare with described reference voltage, then comparative result is fed back to the control end of ring oscillator, change the frequency of ring oscillator, thus by compensating the deviation of output frequency, decrease the impact of parasitic capacitance for frequency-photovoltaic conversion circuit that reference current connects input point, thus make loop stability export the operating frequency of Low Drift Temperature, and improve the frequency accuracy of oscillator.

Further, by eliminating circuit at described frequency-photovoltaic conversion circuit by introducing parasitism, avoid the introducing metal-oxide-semiconductor parasitic capacitance introduced at first node and Section Point place because of described frequency-photovoltaic conversion circuit, therefore in the process of discharge and recharge, reduce the sensitiveness to temperature, avoid the impact of parasitic capacitance on built-in oscillation circuit, improve the temperature characterisitic of frequency-photovoltaic conversion circuit, and then improve the temperature characterisitic of whole system.

Further, in described built-in oscillation circuit, described basic current is produced circuit and is controlled and high-order low level He Ne laser by the low level fine tuning of trimming resistors and a high position for the overriding mirror image circuit of multichannel, thus can by trimming the process deviation of a modification method to output frequency, the frequency reaching 0.1% trims precision, and can cover and wholely trim scope, disconnected joint.

Described built-in oscillation circuit, not only in technique, has higher stability when temperature deviation and supply voltage deviation, export a stable clock signal, and its reference frequency output is wide.

Although the present invention discloses as above with preferred embodiment; so itself and be not used to limit the present invention; have in any art and usually know the knowledgeable; without departing from the spirit and scope of the present invention; when doing a little change and retouching, therefore protection scope of the present invention is when being as the criterion depending on those as defined in claim.

Claims (41)

1. a built-in oscillation circuit, comprises basic current and produces circuit, ring oscillator, frequency-photovoltaic conversion circuit and differential amplifier circuit;

Described basic current produces circuit and comprises the first operational amplifier, the first amplifier tube, trimming resistors and mirror image circuit, described first operational amplifier receives a reference voltage, after described trimming resistors trims, export an intermediate current by the first amplifier tube, described intermediate current exports reference current through described mirror image circuit;

Described ring oscillator produces frequency signal;

Described frequency-photovoltaic conversion circuit comprises switching tube module, charge and discharge electric capacity and output capacitance, described switching tube module receives described reference current and frequency signal, and under the control of described frequency signal, carry out described reference current is charged to described charge and discharge electric capacity and carry out between charge and discharge electric capacity and output capacitance the process that electric charge is redistributed and discharged to described charge and discharge electric capacity, to make described output capacitance output feedack voltage;

The more described feedback voltage of described differential amplifier circuit and described reference voltage also produce control voltage, and described control voltage carries out feedback compensation to the frequency signal of described ring oscillator, export until frequency signal is stable;

It is characterized in that, described frequency-photovoltaic conversion circuit also comprises pulse signal generating circuit and parasitic capacitance eliminates circuit, described pulse signal generating circuit produces the pulse signal of multiple control switch tube module according to described frequency signal, described parasitism elimination circuit comprises the first parasitic elimination circuit and the second parasitism eliminates circuit, described charge and discharge electric capacity comprises the first charge and discharge electric capacity and the second charge and discharge electric capacity, described switching tube module comprises the first switching tube, first charging valve, first discharge tube, second switch pipe, second charging valve, second discharge tube, first anti-crosstalk pipe and the second anti-crosstalk pipe,

Frequency signal, first described in the control termination of described first switching tube connects reference current described in termination, second and connects termination first node, the inversion signal, first of frequency signal described in the control termination of described second switch pipe connects reference current described in termination, second and connects termination Section Point

Described first charge and discharge electric capacity one end connects described first node, other end ground connection, and described second charge and discharge electric capacity one end connects described Section Point, other end ground connection,

The control termination pulse signal of described first charging valve, two links connect between first node and output capacitance respectively, the control termination pulse signal of described second charging valve, two links connect between Section Point and output capacitance respectively, the control termination pulse signal of described first discharge tube, two links are ground connection and first node respectively, the control termination pulse signal of described second discharge tube, two links are ground connection and Section Point respectively

Described first parasitic capacitance is eliminated circuit input end and is connect described pulse signal, exports first node described in termination, and the described second parasitic circuit input end of eliminating connects described pulse signal, exports Section Point described in termination;

The control termination pulse signal of described first anti-crosstalk pipe, two links are connected between described first charging valve and output capacitance, and control termination pulse signal, two links of described second anti-crosstalk pipe are connected between the second charging valve and output capacitance.

2. built-in oscillation circuit as claimed in claim 1, is characterized in that, when the frequency signal of described ring oscillator stablizes output, the value of described frequency signal is relevant with the capacitance of the resistance value and charge and discharge electric capacity that trim resistance.

3. built-in oscillation circuit as claimed in claim 2, it is characterized in that, the output frequency of described built-in oscillator is:

$\mathrm{fout}=\frac{K}{\mathrm{Cc}*(\mathrm{Rp}+\mathrm{Rn})},$

Wherein, fout is the output frequency of described ring oscillator, and Cc is the capacitance of described charge and discharge electric capacity, and (Rp+Rn) is the resistance value of described trimming resistors, and K is proportionality coefficient.

4. built-in oscillation circuit as claimed in claim 1, it is characterized in that, produce in circuit at described basic current, two inputs of described first operational amplifier connect the first link of described reference voltage and the first amplifier tube respectively, export the control end of the first amplifier tube described in termination; First link of the first amplifier tube described in described trimming resistors one end ground connection, another termination, the second link, the output of the first amplifier tube described in the input termination of described mirror image circuit export described reference current.

5. built-in oscillation circuit as claimed in claim 4, it is characterized in that, described mirror image circuit comprises the first mirror image efferent duct, and the control end of the first amplifier tube described in the control termination of described first mirror image efferent duct, the first link of described first mirror image efferent duct export the second connection termination one supply voltage of described reference current, described first mirror image efferent duct.

6. built-in oscillation circuit as claimed in claim 4, it is characterized in that, described mirror image circuit comprises the first mirror image input pipe, second mirror image input pipe, first mirror image efferent duct and the second mirror image efferent duct, second link of the first amplifier tube described in the control termination of described first mirror image input pipe, first of described first mirror image input pipe connects the second link of the second mirror image input pipe described in termination, second of described first mirror image input pipe connects termination one supply voltage, second of described second mirror image input pipe connects the second link of the first amplifier tube described in termination, the control end of the first mirror image input described in the control termination of described first mirror image efferent duct, first of described first mirror image efferent duct connects the second link of the second mirror image efferent duct described in termination, second of described first mirror image efferent duct connects supply voltage described in termination, the control end of the second mirror image input pipe described in the control termination of described second mirror image efferent duct, first link of described second mirror image efferent duct exports described reference current, second link of described second mirror image efferent duct is connected with the first link of one first mirror image efferent duct.

7. built-in oscillation circuit as claimed in claim 4, it is characterized in that, described mirror image circuit is the overriding mirror image circuit of multichannel, described trimming resistors realizes low level frequency departure to described reference current and regulates, and the overriding mirror image circuit of described multichannel realizes high-order low level He Ne laser and described reference current realizes high-end frequency bias adjustment.

8. built-in oscillation circuit as claimed in claim 7, it is characterized in that, described overriding mirror image circuit is common-source common-gate current mirror structure.

9. built-in oscillation circuit as claimed in claim 8, it is characterized in that, the overriding mirror image circuit of described multichannel comprises the first mirror image input pipe, second mirror image input pipe, multiple first mirror image efferent duct and multiple second mirror image efferent duct, second link of the first amplifier tube described in the control termination of described first mirror image input pipe, first of described first mirror image input pipe connects the second link of the second mirror image input pipe described in termination, second of described first mirror image input pipe connects termination one supply voltage, second of described second mirror image input pipe connects the second link of the first amplifier tube described in termination, the control end of the first mirror image efferent duct described in each all connects the control end of described first mirror image input pipe, second of first mirror image efferent duct described in each connects supply voltage described in termination, the control end of the second mirror image efferent duct described in each all connects the control end of described second mirror image input pipe, the described reference current of the connected rear output of first link of described second mirror image efferent duct, described in each, the second link of the second mirror image efferent duct is connected with the first link of one first mirror image efferent duct.

10. built-in oscillation circuit as claimed in claim 9, it is characterized in that, described built-in oscillation circuit comprises M the first mirror image efferent duct, described basic current produces circuit and receives a multidigit control signal, described multidigit control signal comprises He Ne laser position, mirror image circuit regulates position and resistance adjustment position, the ratio value that described He Ne laser position controls N number of described first mirror image efferent duct and described first mirror image input pipe is selected to realize frequency range, described mirror image circuit regulates the ratio value of a position control L described first mirror image efferent duct and described first mirror image input pipe to realize coarse adjustment in frequency range, described resistance adjustment position controls the resistance value of described trimming resistors to realize accurate adjustment in frequency range, wherein, N, L and M is positive integer, described N number of first mirror image efferent duct and L the first mirror image efferent duct are the first different mirror image efferent ducts, and N+L=M.

11. built-in oscillation circuit as claimed in claim 1, it is characterized in that, described switching tube module also comprises the 3rd discharge tube and the 4th discharge tube, the control termination pulse signal of described 3rd discharge tube, two connects described in terminations between the first charge and discharge electric capacity and ground, and the control termination pulse signal, two of described 4th discharge tube to connect described in terminations between the second charge and discharge electric capacity and ground.

12. built-in oscillation circuit as claimed in claim 11, it is characterized in that, described first switching tube, the first charging valve, the first discharge tube, second switch pipe, the second charging valve, the second discharge tube, the first anti-crosstalk pipe, the second anti-crosstalk pipe, the 3rd discharge tube and the 4th discharge tube receive different pulse signals, and described first switching tube, the first charging valve, the first discharge tube, second switch pipe, the second charging valve, the second discharge tube, the first anti-crosstalk pipe, the second anti-crosstalk pipe, the 3rd discharge tube and the 4th discharge tube are metal-oxide-semiconductor.

13. built-in oscillation circuit as claimed in claim 1, is characterized in that, the described first parasitic elimination circuit is identical with the structure of the described second parasitic elimination circuit.

14. built-in oscillation circuit as claimed in claim 13, is characterized in that, the described first parasitic circuit of eliminating has the 3rd node, and the parasitic capacitance of described 3rd node is equal with the parasitic capacitance of described first node, described first parasitic circuit of eliminating comprises the 11 metal-oxide-semiconductor to the 17 metal-oxide-semiconductor, source electrode and the grid of described 11 metal-oxide-semiconductor connect, drain electrode connects described 3rd node, the grid of described 13 metal-oxide-semiconductor connects pulse signal, drain electrode connects described 3rd node, source electrode connects the source electrode of described 12 metal-oxide-semiconductor, the grid of described 12 metal-oxide-semiconductor connects pulse signal, source electrode and drain electrode connect and connect described reference voltage, the drain electrode of described 14 metal-oxide-semiconductor and the 15 metal-oxide-semiconductor all connects described 3rd node, grid and source grounding, the drain electrode of described 16 metal-oxide-semiconductor connects described 3rd node, grid connects pulse signal, source electrode connects the source electrode of described 17 metal-oxide-semiconductor, the grid of described 17 metal-oxide-semiconductor connects described pulse signal, source electrode and drain electrode connect and connect described Section Point.

15. built-in oscillation circuit as claimed in claim 13, is characterized in that, in described frequency-photovoltaic conversion circuit, the described second parasitic circuit of eliminating has the 4th node, and the parasitic capacitance of described 4th node is equal with the parasitic capacitance of described Section Point, described second parasitic circuit of eliminating comprises the 18 metal-oxide-semiconductor to the 24 metal-oxide-semiconductor, source electrode and the grid of described 18 metal-oxide-semiconductor connect, drain electrode connects described 4th node, the grid of described 20 metal-oxide-semiconductor connects pulse signal, drain electrode connects described 4th node, source electrode connects the source electrode of described 19 metal-oxide-semiconductor, the grid of described 19 metal-oxide-semiconductor connects pulse signal, source electrode and drain electrode connect and connect described reference voltage, the drain electrode of described 21 metal-oxide-semiconductor and the 22 metal-oxide-semiconductor all connects described 4th node, grid and source grounding, the drain electrode of described 23 metal-oxide-semiconductor connects described 4th node, grid connects pulse signal, source electrode connects the source electrode of described 24 metal-oxide-semiconductor, the grid of described 24 metal-oxide-semiconductor connects described pulse signal, source electrode and drain electrode connect and connect described Section Point.

16. built-in oscillation circuit as claimed in claim 1, it is characterized in that, described built-in oscillation circuit also comprises many times of frequency dividers, described many times of frequency dividers are arranged between described ring oscillator and frequency-photovoltaic conversion circuit, after described many times of frequency dividers carry out frequency division to described frequency signal, export described frequency-photovoltaic conversion circuit to, to make described frequency-photovoltaic conversion circuit stability work.

17. built-in oscillation circuit as claimed in claim 16, is characterized in that, when the stable output of described frequency signal, described frequency signal is:

wherein, M is the frequency division multiple of described many times of frequency dividers, and fout is the output frequency of described built-in oscillator, and Cc is the capacitance of the first charge and discharge electric capacity, and (Rp+Rn) produces the resistance value of the trimming resistors of circuit for basic current, K is proportionality coefficient.

18. built-in oscillation circuit as claimed in claim 16, it is characterized in that, described many times of frequency dividers comprise the twice frequency divider of multiple cascade.

19. built-in oscillation circuit as claimed in claim 1, it is characterized in that, described differential amplifier circuit comprises the second operational amplifier, resistance and electric capacity, described in one input termination of described second operational amplifier, reference voltage, another input are connect described feedback voltage by described resistance, are exported ring oscillator described in termination, described electric capacity one end is connected between described first operational amplifier and described resistance, and the other end is connected between described first operational amplifier and described ring oscillator.

20., as the built-in oscillation circuit in claim 1 to 19 as described in any one, is characterized in that, described built-in oscillation circuit is arranged at frequency range in the toy remote control equipment of 27MHZ ~ 49MHZ.

21., as the built-in oscillation circuit in claim 1 to 19 as described in any one, is characterized in that, described built-in oscillation circuit is arranged at frequency range in the wireless control apparatus of 315MHz or 433MHZ.

22., as the built-in oscillation circuit in claim 1 to 19 as described in any one, is characterized in that, described built-in oscillation circuit is arranged at frequency range in the infrared remote control equipment of 38KHz.

23. 1 kinds of built-in oscillation circuit, comprise basic current and produce circuit, ring oscillator, frequency-photovoltaic conversion circuit and differential amplifier circuit;

Described basic current produces circuit and comprises the first operational amplifier, the first amplifier tube, trimming resistors and mirror image circuit, described first operational amplifier receives a reference voltage, after described trimming resistors trims, export an intermediate current by the first amplifier tube, described intermediate current exports reference current through described mirror image circuit;

Described ring oscillator produces frequency signal;

Described frequency-photovoltaic conversion circuit comprises switching tube module, charge and discharge electric capacity and output capacitance, described switching tube module receives described reference current and frequency signal, and under the control of described frequency signal, carry out described reference current is charged to described charge and discharge electric capacity and carry out between charge and discharge electric capacity and output capacitance the process that electric charge is redistributed and discharged to described charge and discharge electric capacity, to make described output capacitance output feedack voltage;

The more described feedback voltage of described differential amplifier circuit and described reference voltage also produce control voltage, and described control voltage carries out feedback compensation to the frequency signal of described ring oscillator, export until frequency signal is stable;

It is characterized in that, described frequency-photovoltaic conversion circuit also comprises pulse signal generating circuit, described pulse signal generating circuit produces the pulse signal of multiple control switch tube module according to described frequency signal, and described switching tube module comprises the first switching tube, the first charging valve, the first discharge tube and the first anti-crosstalk pipe; Frequency signal, first described in the control termination of described first switching tube connects reference current described in termination, second and connects termination first node, described charge and discharge electric capacity one end connects described first node, other end ground connection, the control termination pulse signal of described first charging valve, two links connect between first node and output capacitance respectively, the control termination pulse signal of described first discharge tube, two links are ground connection and first node respectively, and control termination pulse signal, two links of described first anti-crosstalk pipe are connected between described first charging valve and output capacitance.

24. built-in oscillation circuit as claimed in claim 23, it is characterized in that, described switching tube module also comprises the 3rd discharge tube, and the control termination pulse signal of described 3rd discharge tube, two to connect described in terminations between charge and discharge electric capacity and ground to discharge further to described charging capacitor.

25. built-in oscillation circuit as claimed in claim 24, it is characterized in that, described first switching tube, the first charging valve, the first discharge tube, the first anti-crosstalk pipe and the 3rd discharge tube receive different pulse signals, and described first switching tube, the first charging valve, the first discharge tube, the first anti-crosstalk pipe and the 3rd discharge tube are metal-oxide-semiconductor.

26. built-in oscillation circuit as claimed in claim 23, is characterized in that, when the frequency signal of described ring oscillator stablizes output, the value of described frequency signal is relevant with the capacitance of the resistance value and charge and discharge electric capacity that trim resistance.

27. built-in oscillation circuit as claimed in claim 26, it is characterized in that, the output frequency of described built-in oscillator is:

$\mathrm{fout}=\frac{K}{\mathrm{Cc}*(\mathrm{Rp}+\mathrm{Rn})},$

Wherein, fout is the output frequency of described ring oscillator, and Cc is the capacitance of described charge and discharge electric capacity, and (Rp+Rn) is the resistance value of described trimming resistors, and K is proportionality coefficient.

28. built-in oscillation circuit as claimed in claim 23, it is characterized in that, produce in circuit at described basic current, two inputs of described first operational amplifier connect the first link of described reference voltage and the first amplifier tube respectively, export the control end of the first amplifier tube described in termination; First link of the first amplifier tube described in described trimming resistors one end ground connection, another termination, the second link, the output of the first amplifier tube described in the input termination of described mirror image circuit export described reference current.

29. built-in oscillation circuit as claimed in claim 28, it is characterized in that, described mirror image circuit comprises the first mirror image efferent duct, and the control end of the first amplifier tube described in the control termination of described first mirror image efferent duct, the first link of described first mirror image efferent duct export the second connection termination one supply voltage of described reference current, described first mirror image efferent duct.

30. built-in oscillation circuit as claimed in claim 28, it is characterized in that, described mirror image circuit comprises the first mirror image input pipe, second mirror image input pipe, first mirror image efferent duct and the second mirror image efferent duct, second link of the first amplifier tube described in the control termination of described first mirror image input pipe, first of described first mirror image input pipe connects the second link of the second mirror image input pipe described in termination, second of described first mirror image input pipe connects termination one supply voltage, second of described second mirror image input pipe connects the second link of the first amplifier tube described in termination, the control end of the first mirror image input described in the control termination of described first mirror image efferent duct, first of described first mirror image efferent duct connects the second link of the second mirror image efferent duct described in termination, second of described first mirror image efferent duct connects supply voltage described in termination, the control end of the second mirror image input pipe described in the control termination of described second mirror image efferent duct, first link of described second mirror image efferent duct exports described reference current, second link of described second mirror image efferent duct is connected with the first link of one first mirror image efferent duct.

31. built-in oscillation circuit as claimed in claim 28, it is characterized in that, described mirror image circuit is the overriding mirror image circuit of multichannel, described trimming resistors realizes low level frequency departure to described reference current and regulates, and the overriding mirror image circuit of described multichannel realizes high-order low level He Ne laser and described reference current realizes high-end frequency bias adjustment.

32. built-in oscillation circuit as claimed in claim 31, it is characterized in that, described overriding mirror image circuit is common-source common-gate current mirror structure.

33. built-in oscillation circuit as claimed in claim 32, it is characterized in that, the overriding mirror image circuit of described multichannel comprises the first mirror image input pipe, second mirror image input pipe, multiple first mirror image efferent duct and multiple second mirror image efferent duct, second link of the first amplifier tube described in the control termination of described first mirror image input pipe, first of described first mirror image input pipe connects the second link of the second mirror image input pipe described in termination, second of described first mirror image input pipe connects termination one supply voltage, second of described second mirror image input pipe connects the second link of the first amplifier tube described in termination, the control end of the first mirror image efferent duct described in each all connects the control end of described first mirror image input pipe, second of first mirror image efferent duct described in each connects supply voltage described in termination, the control end of the second mirror image efferent duct described in each all connects the control end of described second mirror image input pipe, the described reference current of the connected rear output of first link of described second mirror image efferent duct, described in each, the second link of the second mirror image efferent duct is connected with the first link of one first mirror image efferent duct.

34. built-in oscillation circuit as claimed in claim 33, it is characterized in that, described built-in oscillation circuit comprises M the first mirror image efferent duct, described basic current produces circuit and receives a multidigit control signal, described multidigit control signal comprises He Ne laser position, mirror image circuit regulates position and resistance adjustment position, the ratio value that described He Ne laser position controls N number of described first mirror image efferent duct and described first mirror image input pipe is selected to realize frequency range, described mirror image circuit regulates the ratio value of a position control L described first mirror image efferent duct and described first mirror image input pipe to realize coarse adjustment in frequency range, described resistance adjustment position controls the resistance value of described trimming resistors to realize accurate adjustment in frequency range, wherein, N, L and M is positive integer, described N number of first mirror image efferent duct and L the first mirror image efferent duct are the first different mirror image efferent ducts, and N+L=M.

35. built-in oscillation circuit as claimed in claim 23, it is characterized in that, described built-in oscillation circuit also comprises many times of frequency dividers, described many times of frequency dividers are arranged between described ring oscillator and frequency-photovoltaic conversion circuit, after described many times of frequency dividers carry out frequency division to described frequency signal, export described frequency-photovoltaic conversion circuit to, to make described frequency-photovoltaic conversion circuit stability work.

36. built-in oscillation circuit as claimed in claim 35, is characterized in that, when the stable output of described frequency signal, described frequency signal is:

wherein, M is the frequency division multiple of described many times of frequency dividers, and fout is the output frequency of described built-in oscillator, and Cc is the capacitance of the first charge and discharge electric capacity, and (Rp+Rn) produces the resistance value of the trimming resistors of circuit for basic current, K is proportionality coefficient.

37. built-in oscillation circuit as claimed in claim 35, it is characterized in that, described many times of frequency dividers comprise the twice frequency divider of multiple cascade.

38. built-in oscillation circuit as claimed in claim 23, it is characterized in that, described differential amplifier circuit comprises the second operational amplifier, resistance and electric capacity, described in one input termination of described second operational amplifier, reference voltage, another input are connect described feedback voltage by described resistance, are exported ring oscillator described in termination, described electric capacity one end is connected between described first operational amplifier and described resistance, and the other end is connected between described first operational amplifier and described ring oscillator.

39., as the built-in oscillation circuit in claim 23 to 38 as described in any one, is characterized in that, described built-in oscillation circuit is arranged at frequency range in the toy remote control equipment of 27MHZ ~ 49MHZ.

40., as the built-in oscillation circuit in claim 23 to 38 as described in any one, is characterized in that, described built-in oscillation circuit is arranged in the wireless control apparatus of frequency range 315MHz or 433MHZ.

41., as the built-in oscillation circuit in claim 23 to 38 as described in any one, is characterized in that, described built-in oscillation circuit is arranged at frequency range in the infrared remote control equipment of 38KHz.